Treatment of the ores of certain metals.



ROBERT LANCE, OF PARIS, FRANCE.

TREATMENT OF THE ORES OF CERTAIN METALS.

No Drawing.

which the following is a complete specification.

This invention has for its object to provide an improved process for the treatment of ores of certain metals such as zinc, copper, cadmium, cobalt, nickel, etc., and more particularly pyritie, oxidized, carbonated, silicatcd and other ores with a view of extracting the useful elements contained therein.

The improved process consists in effecting a complete cycle, by converting the metals to be extracted into the form of chlorids, then precipitating them from the solutions while recovering or regenerating the substances which have been used for effecting the chloridization.

The first stage or stage of chloridization may take place in the cold or in heat.

In one embodiment of the invention, the metals are converted directly or indirectly into sulfates from which a solution is made by leaching. To this solution there is added a quantity of earthy alkaline 'ehlorid sufli cient to fix in the form of insoluble sulfate the sulfuric acid contained in the dissolved salts, while the metals of the latter salts remain in solution in the form of chlorids. In the second case the metals to be extracted are converted directly into the form oi chlorid either by the action of gaseous hydrochloric acid at a temperature varying according as it is desired to extract certain metals by mechanical removal or by volatil-v izing or by leaching; or by roasting the ore with the addition of an earthy alkaline chlorid and pyrites if necessary in the pres ence of air and water. l

The second stage after the chloridization consists in bringing the metals into solution and precipitatingthem in the Following manner m The chloridizcd solutions obtained in one or the other case are acted upon by an earthy alkaline. oxychlorid which precipitates the metal in the form of a hydroxid WllllO rc- Specification of Letters Patent.

Patented Nov. 20, 11.91%...

Application filed June 2 4, 1914. Serial No. 847,137.

generating the earthy alkaline chlorid, which is necessary either for the cold chloridization process or for the manufacture of hydro chloric acid gas or for the chloridizing roasting operation in hot chloridizing.

As an example of a cold chloridization, there will now be described the treatment of a mixed ore such as a blende, pyrites, galena having the following composition: Zinc lG.00 lead 8copper 922--sulfur 19-iron 14--alumina 4silica 29-lime l.S- 1nagnesia 1.20.

The operation is effected in a cast iron vessel provided with a powerful stirring apparatus and fitted with a. cover having an escape pipe and a device for enabling; the ore to he charged into the vessel Without allowing the gases to escape therefrom. The acid liquor for one ton of ore consists of 720 kg. of sulfuric acid with 900 kg. of water. This liquor is heated to boiling point, whereupon by means of the charging device, the ore. heated to 200 degrees C. is charged into the liquor. The mixture gradually thickens and at the same time the sulfur begins to be given off. A mixture of sulfurous acid, Water vapor, and a small quantity of sulfur vapor escapes from the vessel.

The mixture having now acquired a pasty consistency is charged into cast iron retorts heated to about 450500 degrees C. The sulfur distils off while the first re-action is being completed. A mixture of sulfur vapor, water vapor, sulfurous acid and sulfuric acid issues from the retort. @n leaving the retort the ore in pieces is charged into a v action of the hydrated-sulfuric anhydrid causes the acid attack to produce its maximum effect. A slight current of. air mixed Eli till

i. l tifb ever advisable simple in its application cases where the ore contains but little iroo, or if it is desired to effect the preoxi fu-liloil in the dissolved state by ordinary methods the acid roasting operation is stog iped at 500 degrees C. after the recovery the sulfur, so as to avoid attacking the roated ore on issuing from the furnace is washed with or without pressure by n us of a solution acidified with sulfuric "d if the roasting has been efiected at 800 es C. or by means of ordinary Water been stopped at 500 degrees C.

A leachim oieration under air ressure ipansion several times repeated in rotm'" apparatus of the Alsing'type, en a maximum yield to he obtained.

. no solid portion is separated from the liquor containing the soluble sulfates by lug said liquor through afilte-ring tus (filter press, vacuum filter, turbineg.

4 ion ifnecessary, with a solution of an hy alkaline chlorid GaChJBaCl which produces an insoluble sulfate:

ZnSOd-Caol CaSO +ZnCl The base of the'chlorid is precipitated in. the form of sulfate and the metals correspending to the sulfates remain in solution in the form of chlorids.

ln the example of hot chloridisation, the 1. d ore'is charged into a muiiie furnace to that herei'nhefore referred to and i.- hta'ted to a temperature of between. 700 and 900 degrees C., but instead of using ater vapor and air, there is injected a stream of moist hydrochloric acid obtained by reatin'g an earthy alkaline chlorid with sulfuric acid. In this operation it is how to employ instead of the earthy alkaline chlorid an alkaline chlorid because its sulfate generally retains the same value as that of the chlorid from which it is derived:

For this method of chlori icing by means of hydrochloric acid gas stunted a process of ehloridizing without acid yn'eparation. This iro'cess which is emisumptiou of earthy al'laline 1t rii-liness instead of sulfuric acid prone s con, sts m adding to the mixture of ore and earthy alkaline chlorid. a certain amount of 1Y011 pyrites and in treating the chlorid but This mass in the aforesaid furnace in the presence air and steam. v Ul'he reaction which is then produced by iquor is then treated, after neutrali-' there may be sub entails a greater erni-its the use of o rites of more or less chlorid whic h has eefii i V. .-'4. ,iw, hw-

. By th1s operation the 21m; 1s prempitated 1n the action of the heat, oigygen andsteam, may be represented by the following equation in which it is assumed that a zinc carbonate ore is being treated.

silicate ore the reaction is v. -v v s milai but more complex.

This reaction taltes'pla'ce only' at a temperature of about 900 degrees C. and it causes the evolution of sulfurous acid'and chlorin in addition to the above stated 5 products. I

The chlorids that arefcarried'ofl" are con doused in a scrubber of any suitable type by means of water acidified with the hydrochloric acid that escapes frointhe furnace, so'as'to convert into chloride the oXychlO- ricls which may have formed during theoperation. The solutions are then neutralized with carbonate oflimef In the case of oxidized, carhonated'cr silicated ores from lime-stone rock, the limestone is first converted by calcination into quick lime which latter is dissolved by a boiling solution of calcium chlorid or sodium chlor'id, whereby-the lime is converted into calcium oxy-chlorid or sodium calcium oxy- I always an aqueous so'lutioh 'o. chlorid, namely in the attic tisejoilj ores above mentioned eh'l rj '1 o f lzincl} The zinc lather! pree'ipitatedfrom the so lutions by adding" to the latter a sufficient quantity of eartlij alkaline "oxy chlorid; and in particular irrthe case of oxicli'2edi,"car

honatecl silicate'd' ores front limestone rock, by addingthe solution of 'jc'alciumfoxypreviously produced.

the form of hydrated oxid with a production of the earthy alkaline chlorid.

By this means the earthy alkaline chlorid has been recovered. which has served for the chloridization of the sulfate liquor, for the manufacture of the hydrochloric acid gas, or for the direct: treatment with pyrites as well as for the treatment of the limestone ores.

In the case of chloridization in the cold it is sufficient to concentrate the liquor to its for chloridizing the ore. The mother liqnors are then returned to the scrubbers as before.

The whole of this process applies equally to the treatment of arsenic-sulfur ores or antimony-sulfur ores or of a mixture of both.

What I claim is:

The herein described process of extractingmetals lrom their ores which consists in treating the ore by a reagent to obtain a solution of a chlorid of the metal, treating the said solution with an oXy-chlorid of an alkaline earth, thereby precipitating the metal in the form of a hydroxid, and snhseqncntly separating the metal hydroxith from the regencratial alkaline. earth ehlorid. lo testimony whereof I have hereunto set my hand at laris l rance, this tenth day of June, 1914.

ROBERT LANCE. In the presence of (Has 1.. Presser, Louis CDQUILLAYL. 

